Organometallic orthophosphates



United States Patent 3,275,668 .ORGANOMETALLIC ORTHOPHUSPHATES AnthonyJ. Revukas, Cranford, N..l., assignor to Cities Service Oil Company, acorporation of Delaware No Drawing. Filed July 31, 1961, Ser. No.127,840 8 Claims. (Cl. 260---429.3)

This application is a continuation-in-part of my application S.N.27,294, filed on May 6, 1960, now abandoned.

This invention relates to novel metallic orthophosphate compounds and togasolene compositions including such compounds.

The use of lead compounds to increase the octane rating of gasolene isextremely common. Unfortunately, the addition of lead, whilesubstantially increasing the octane ratings of gasolenes to which it isadded, at the same time has several drawbacks. Of these drawbacks themost serious is probably the tendency of the lead to increaseundesirable surface ignition in the combustion chambers of the internalcombustion engines in which the leaded gasolene is used. It has been thepractice previously to utilize various phosphorous compounds in anattempt to reduce or prevent such surface ignition, but the use of suchcompounds has generally led to additional difiiculties such as leaddeposits on cylinder heads and valves.

It is an object of the present invention to provide novel metallicorthophosphate compounds adapted for use in improved gasolenecompositions.

It is another object of the invention to provide an improved gasolenecomposition especially adapted to resist surface ignition.

The novel compounds of the present invention are orthophosphates oftitanium or zirconium. Preferred orthophosphates of these metals may berepresented by the general formula RO\(? M PO] R O X wherein Mrepresents zirconium or titanium, X is a number equal to the valence ofthe metal M and R and R each represent a hydrocarbon radical having from2 to 30 carbon atoms. In such compounds titanium and zirconium each havea valence of either 3 or 4 depending upon the starting material used.Preparation of these compounds is discussed in greater detail below. Rand R may represent identical or different hydrocarbon radicals. Whileany hydrocarbon radicals having between 2 and about 30 carbon atoms andsoluble to the required extent in gasolene may be used, at least one ofR and R preferably represents a branched chain hydrocarbon radical. Suchradicals are generally more soluble in gasolene than other hydrocarbonradicals, thereby facilitating the use of the novel compounds of thepresent invention as gasolene additives. Since chains of more than about30 carbon atoms are generally difiicult or impossible to dissolve ingasolene compositions, it is preferred that the hydrocarbon radicals ofthe orthophosphates of the present invention each have been 2 and about30 carbon atoms.

Compounds of the present invention having branched chain alkylhydrocarbon radicals include for instance the following:

titanium tetra (bis(Z-methylpropyl) orthophosphate) Zirconium tetra(bis(3-butyloctyl) orthophosphate) titanium tetra(bis(S-pentylhexadecyl) orthophosphate) titanium tetra(bis(Z-ethyl-S-butyltridecyl) orthophosphate) zirconium tetra(bis(Z-propyldecyl) orthophosphate) titanium tetra(bis(2,4-diethyloctyl) orthophosphate) titanium tetra(bis(Z-methyloctyl) orthophosphate) zirconium tetra (bis(methylethyl)orthophosphate) titanium IV di(2ethylhexyl), tributyl orthophosphatetitanium tetra (bis(methylethyl) orthophosphate) titanium tetra(Z-methylpropyl, methylethyl orthophosphate) titanium tetra(Z-methyloctyl, 2-propyldecyl orthophosphate) titanium IVdi(2-ethylhexyl), di(methylethyl), di(2- methylpropyl) di3-butyloctosyl) orthophosphate titanium tri (bis(Z-ethylhexyl)orthophosphate) zirconium tetra (bis(Z-ethylhexyl) orthophosphate)zirconium tri (Z-ethylhexyl, Z-methylpropyl orthophosphate) Compounds ofthe present invention having alkylaryl hydrocarbon radicals include forinstance, the following:

titanium tetra (bis(octylphenyl) orthophosphate) zirconium tetra(bis(methylphenyl) orthophosphate) titanium tetra (bis(tricosylphenyl)orthophosphate) zirconium tetra (bis(pentylphenyl) orthophosphate)titanium tetra (octylphenyl, pentylphenyl orthophosphate) titanium tri(bis(methylphenyl) orthophosphate) zirconium tri (bis(hexylphenyl)orthophosphate) Compounds of the present invention having both alkyl andalkylaryl hydrocarbon radicals include, for instance, the following:

zirconium tetra (Z-ethylhexyl, methylphenyl) orthophosphate titanium IVdi(2-ethylhexyl), diQoctylphenyl), 2- propyldecyl, methylethyl,di(2-methyloctyl) orthophosphate Compounds of the present inventionhaving straight chain hydrocarbon radicals include for instance thefollowing:

zirconium tetra (bis(octyl) orthophosphate) titanium tetra (bis(ethyl)orthophosphate) titanium tetra (methyldecyl orthophosphate) zirconium IVdibutyl, diheXyl, ethylhexyl, dipentyl orthophosphate titanium tetra(octylphenyl, hexyl orthophosphate) zirconium tetra (2-ethylhexyl, butylorthophosphate) zirconium tetra (pentacosyl, hexadecyl orthophosphate)titanium tri (bis(ethyl) orthophosphate) zirconium tri (Z-ethylhexyl,butyl orthophosphate) The novel compounds described above are especiallyuseful as gasolene additives in forming novel gasolene compositionsadapted to resist surface ignition. In addition to resisting surfaceignition, these additives generally inhibit rust and carburetor icing.In accordance with a preferred embodiment of the present invention agasolene composition is provided which comprises a major proportion of aleaded hydrocarbon base fuel boiling in the gasolene range andcontaining between about 0.001 and about 5.0 theories of a titanium orzirconium orthophosphate. Such metallic orthophosphate preferably is ofthe type described above having the general formula RO (H) M[ so] RO 1By the term leaded gasolene, leaded hydrocarbon base fuel boiling in thegasolene range and similar terms is meant a petroleum fraction boilingin the gasolene boiling range (e.g., between about and about 450 F.) towhich has been added a small amount, such as between about 0.1 and about6.0 cc. per gallon, of a metalloorganic antiknock compound such astetraethyl lead (TEL), tetramethyl lead (TML), tetraisopropyl lead, etc.Lead is frequently present in gasolene compositions of the presentinvention in the form of TEL, TML or mixtures of the same which may bepresent in suitable amounts such as between about 0.1 and about 6.0 cc.per gallon of gasolene composition, more usually between about 0.5 andabout 4.0 cc. per gallon.

The novel metallic orthophosphates described above for use in leadedgasoline compositions in accordance with the present invention arepresent in suitable amounts such as between about 0.001 and about 5.0theories, preferably between about 0.02 and about 2.0 theories. The termtheory is intended in this context to designate the amount of additiverequired for the metal in the additive to react stoichiometrically withthe lead in the compound such as TEL to produce the appropriate compoundsuch as lead metatitanate.

In addition to the above described titanium and lead compounds, gasolenecompositions contemplated by the present invention may include one ormore other ingredients such as lead scavengers, gum inhibitors,lubricants, rust inhibitors, metal deactivators or other special purposeadditives.

Lubricants suitable for use in the above described gasolene compositionsmay include, for instance, light hydrocarbon lubricating oils havingviscosities at 100 F. of between about 50 and about 200 SayboltUniversal seconds (SUS) and viscosity indexes (VI) of between about 30and about 120 with oil having a viscosity of about 100 SUS beingpreferred. Such oils may be present in suitable amounts such as betweenabout 0.1 and about 1.0 volume percent of the gasolene composition.

When using lead compounds such as TEL, it is frequently found desirableto include with the lead a suitable lead scavenger for reducing thedeposit of lead compounds within the combustion chamber. Such leadscavengers include for example halohydrocarbon compositions such asethylene dibromide and ethylene dichloride.

Gum inhibitors suitable for use in the above described gasolenecompositions include conventional gum inhibitors such as2,6-ditertiary-butylpara cresol. Such gum inhibitors may be present insuitable amounts such as between about 0.001 and about 0.006 volumepercent of the gasolene composition. Likewise, a suitable metaldeactivator is for example N,N'disalicylidene-1,2-diaminopropane.

An especially valuable titanium compound of the type described above foruse in gasolene compositions of the type described above is titaniumtetra (bis(2-ethylhexyl) orthophosphate) having the formula Ti OP(O)OOHz.OH

and hereinafter referred to as TIP.

Gasolene compositions of the present invention may be illustrated by thefollowing examples. In most of these examples the gasolene compositionsof the present invention are described as containing TIP. While TIP andthe corresponding zirconium compound are preferred additives for use insuch gasolene compositions, it should be understood that any of theother novel additive compounds contemplated by the invention, such asthose described above, may be used in such gasolene compositions inplace of or in addition to the TIP.

Example 1 A gasolene composition having excellent surface ignitioncharacteristics may be prepared by adding the following ingredients to asuitable base gasolene:

TEL2.2 cc. per gallon TIP-0.05 theory The base gasolene used in blendingthis and other gasolene compositions of the invention may be a gasolenehaving the following characteristics:

Another suitable gasolene composition is prepared by adding thefollowing ingredients to a suitable base gasolene:

T EL2.2 cc. per gallon TIP0.l theory Example 3 Another suitable gasolenecomposition is prepared by adding the following ingredients to asuitable base gasolene:

T EL-0.5 cc. per gallon TIP0.25 theory Example 4 Another suitablegasolene composition is prepared by adding the following ingredients toa suitable base gasolene:

TEL-4.0 cc. per gallon TIP-0.5 theory Lubricating oil 1.0 volume percent(100 SUS, VI)

Example 5 Another suitable gasolene composition is prepared by addingthe following ingredients to a suitable base gasolene:

TEL6.0 cc. per gallon TIP-50 theory Example 6 Another suitable gasolenecomposition is prepared by adding the following ingredients to asuitable base gasolene:

TEL-0.1 cc. per gallon TIP-0.005 theory Example 7 Another suitablegasolene composition is prepared by adding the following ingredients toa suitable base gasolene:

TEL1.5 cc. per gallon TIP0.01 theory Lubricating oil 0.1 volume percentSUS, 95 VI) Example 8 Another suitable gasolene composition is preparedby adding the following ingredients to a suitable base gasolene:

TEL3.0 cc. per gallon Zirconium tetra bis (octylphenyl) orthophosphate2.0 theory Example 9 Another suitable gasolene composition is preparedby adding the following ingredients to a suitable base gasolene:

TEL2.0 cc. per gallon Titanium tetra bis(octylphenylorthophosphate- 0.5theory Example Another suitable gasolene composition is prepared byadding the following ingredients to a suitable base gasolene:

TEL-22 cc. per gallon TIP-0.1 theory Lubricating oil 0.25 volume percent(100 SUS, 95 VI) Novel additive compounds of the type described abovemay be prepared in any suitable manner. According to one method ofpreparation, a suitable organic hydrogen phosphate or a mixture of suchphosphates is placed in a reaction flask together with about half itsvolume of a suitable solvent such as dry toluene. The reaction flask ispreferably equipped with a mechanical stirrer, thermometer, gas inlettube, reflux condenser and a pressure equalizing funnel with its longstem dipping into the solution. The temperature in the reaction flask israised to between about 110 and about 130 C. while stirring vigorouslyand titanium or zirconium tetrachloride with an equal volume of thesolvent is added in spurts by means of the pressure equalizing deliveryfunnel. The tetrachloride is preferably introduced in amounts of about1.1 moles of tetrachloride for each 4 moles of the organic hydrogenphosphate. Hydrogen chloride is evolved copiously by the reaction.Stirring and heating under reflux to 130 C. is continued until evolutionof hydrogen chloride stops. Removal of by product hydrogen chloride ispromoted by flushing the reaction flask with dry nitrogen by means ofthe gas inlet tube. The solvent is removed by distillation at reducedpressure such as 10 to 80 millimeters, the final temperature being about130 C. The yield of product is usually between about 85 and about 95% oftheory based on hydrogen phosphate.

In compounds prepared as described immediately above, the titanium orzirconium has a valence of 4. Similar compounds in which these metalshave a valence of 3 may be prepared in a similar manner, e.g., by usingtitanium or zirconium trichloride rather than tetrachloride as astarting material.

Example 11 In the production of TIP by means of the above procedure 2000grams of commercial di(2-ethylhexyl) hydrogen phosphate (6 moles) and330 grams (1.7 moles) of titanium tetrachloride were brought intoreaction. The resulting solvent-free crude product was washed with waterto remove acidic materials, taken up in half its volume of normalpentane, and dried over anhydrous sodium sulfate. After filtering, thepentane was removed by distillation with the final temperature being 130C. at 20 millimeters pressure. The yield of dark, amber colored liquidTIP was 1900 grams or 95% of theory based on acid phosphate. Percentagesof titanium and phosphorous obtained on analysis were as follows:

Theory: Titanium, 3.59%; phosphorous, 9.29%. Actually found: Titanium,3.70%; phosphorous, 8.94%.

This TIP had a viscosity at 100 F. of 1337 SUS and at 210 F. of 180 SUS.The density of this TIP at 20 C. was 1.055.

In forming the TIP as described above the reaction is formulated asfollows:

Example 12 In order to demonstrate the usefulness of novel compounds ofthe type described above which include alkylaryl radicals as gasoleneadditives, titanium tetra (bis- 0 (octylphenyl) orthophosphate) wasprepared in accordance with the general method of preparation describedabove. This compound was solid but was moderately soluble in gasoleneand is, therefore, suitable as a gasolene additive.

Example 13 Another titanium orthophosphate containing branched chainhydrocarbon radicals was prepared by reacting 0.2 mole each ofmono'butyl hydrogen phosphate, dibutyl hydrogen phosphate anddi(2-ethylhexyl) hydrogen phosphate with 0.22 mole titaniumtetrachloride in the manner described above. A 92% yield based ontitanium tetrachloride was obtained of titanium IV di(2'e-thylhexyl)-tributyl orthophosphate having the formula:

This compound was a resinous amber colored solid which was soluble ingasolene. An analysis for titanium yielded the following results:

Theory: 6.56%. Actually found: 6.55%.

Example 14 Zirconium orthophosphate was prepared according to thegeneral procedure described above by reacting 0.11 mole of zirconiumtetrachloride with 0.40 mole of di(2- ethylhexyl) hydrogen phosphate inthe presence of 300 milliliters of toluene. The product was zirconiumtetra (bis (Z-ethylhexyl) orthophosphate) having the formula:

In order to evaluate the characteristics of gasolene compositions of thepresent invention, three separate gasolene compositions (A, B, and C)were prepared. These gasolene compositions contained metallicorthophosphate additives of the present invention as indicated in TablesI and II below.

Gasolene compositions A and B used the base gasolene described above inconnection with Example 1 with 2.2 cc. per gallon of TEL added. Gasolenecomposition C also used a base gasolene having the same properties asthe base gasolene of Example 1. The base gasolene of Example C alsocontained 2.2 cc. per gallon of TEL but had been stored for a shorterperiod of time .prior to the tests described below than had the basegasolenes of gasolene compositions A and B. The base gasolenes ofgasolene compositions B and C also contained 0.25 volume per percent ofSUS (95 VI) light lubricating oil. The base gasolenes of gasolenecompositions A, B and C thus differed from the compositions A, B and Crespectively only in the presence or absence of the metallicorthophosphate additives of the present invention. The gasolenecompositions A, B and C, as well as their respective base gasolenes weresubjected to both single cylinder and multi-cylinder engine deposittests as described below.

The single cylinder engine deposit tests were run in CPR engines havingL head assemblies and compression ratios of 7 to 1. Each test consistedof alternating periods of operation under idling conditions for 50seconds followed by operation under full load conditions for 150seconds. These cycles were continued for a total test time of at least40 hours for each test. During these tests the engine air intaketemperature was maintained at F. while the oil temperature wasmaintained at 160 F. and the coolant temperature at F. During the idlingportions of the tests the engines were operated with an air to fuelratio of 12 to 1 at 600 r.p.m. while during 7 the full load portions ofthe tests the engines were operated with air to fuel ratios of 13 to land at 900 r.p.m. During the test, the number of wild pings (indicatingpreignition) was counted by an Erwin Instrument Co. Wild dicates clearlythat the addition of the zirconium or titanium orthophosphatesubstantially reduced the octane number increases due to engine depositsas well as the LIB requirements. For instance, with TIP in the gaso-TABLE IL-MULTICYLINDER ENGINE DEPOSIT TEST Octane Requirement LIBRequirements Increase RI) Base Base Gasolene Gasolcnc Theories ofGasolene Composi- Orthophosphate Additive Additive tion Without WithWithout With additive additive additive additive TIP 0.05 14. 5. 5 85 55TIP 0.10 14. 5 4. 5 C Zirconium tetra (bis (Z-ethyl- 0.20 24.8 5.2 100+60 hexyl) orthophosphate).

Ping Counter. At the end of the test the average of the wild pings perhour was determined by plotting the total wild pings versus time andtaking the slope of the curve. This measurement served as a reliableindication of the surface ignition characteristics of the fuel beingtested.

The multi-cylinder engine deposit tests were run in 1958 OldsmobileRocket engines having compression ratios of 10 to 1. The total time ofeach of these tests was 120 hours of operation 'in cycles of 50 secondsoperation under idling conditions followed by 150 seconds operationunder load conditions to develop twelve brake horsepower. During theidle portions of the cycle the engines were operated with an air to fuelratio of 12 to 1 at a speed of 600 r.p.m. and with a coolant temperatureof 160 F. During the load portions of the test the engines were operatedwith an air to fuel ratio of 14 to 1 at 2000 r.p.m. and with a coolanttemperature of 160 F. Oil temperature was not controlled during thesetests. At intervals of 16 to 24 hours the octane requirement increase(ORI) was obtained by full throttle operation at 1000 r.p.m. usingprimary reference fuels and varying spark advance for trace knock. Atthe end of the test the LIB requirement (leaded isooctane-benzenereference fuel with 3 cc. per gallon TEL to yield trace rumble) wasobtained. The LIB requirement was obtained at 1500 r.p.m. and was theLIB fuel needed to prevent rumble at wide open throttle.

The results of the single cylinder engine deposit test on the gasolenecompositions A, B and C and their respective base gasolenes describedabove are given in Table I below while the results of the multicylinderengine deposit tests are given in Table II.

Table I shows clearly that the addition to the titanium or zirconiumorthophosphate to the base gasolenes resulted in gasolene compositionshaving remarkably good surface ignition characteristics as evidenced bya decrease in wild pings as compared with the base gasolenes which didnot contain these additives. Likewise, Table II inlene the Oldsmobileengines tolerated a three times greater amount of the surface ignitioninducing aromatic benzene than did the base gasolene, thereby furtherattesting to the high surface ignition resistance quality of thegasolene compositions containing the metallic orthophosphates of thepresent invention.

In order to evaluate the ability of TIP to inhibit carburetor icing,carburetor icing tests were conducted in a standard six cylinderChevrolet engine having a displacement of 216.5 cubic inches and ratedat 86 horsepower at 3400 r.p.m. The following test conditions wereemployed.

Intake air 38 to 40 F.

Relative humidity 100% Engine load 10 horsepower Engine speed 1500r.p.m.

Idle speed 450 to 500 r.p.m.

Temperature of fuel entering carburetor 48 to 50 F. Air to fuel ratio12.3 to 12.5

Carburetor icing tendencies of gasolenes are measured by this test whenthe engine is operated under the constant severe icing conditionsoutlined above. The engine run is started with the throttle late at 34F. The ice forming characteristics of the test gasolene normally controlthe engine operating cycle. During the test the engine is run at 1500r.p.m. for 1 to 2 /2 minutes. At the end of the 1500 r.p.m. operatingcycle the throttle is returned to the idle speed of 450 to 500 r.p.m.The engine is idled for 30 seconds and if stalling does not occur theidle speed r.p.m. is observed. A reduction in idle speed of more than100 r.p.m. is considered a partial stall.

The base gasolene used in the carburetor icing had the followingvolatility characteristics:

tests Gravity API" 60.0

Reid vapor pressure lbs 10.9

ASTM distillation:

I.B.P. F 81 5% evaporated F 102 10 F 112 30 F 146 50 F 188 70 F 250 F315 F 335 BR F 359 Recovery percent 97.4 Residue percent 1.1 Losspercent 1.5

A total of 12 test runs were made. In four of these runs the basegasolene contained no additive except 2.2 cc. per gallon TEL. In anotherseries of four runs the base gasolene used contained 0.024 theory TIPwhile in the remaining four runs the base gasolene contained 0.096theory TIP. The results of these carburetor icing tests are shown inTable III below.

TABLE IIL-STALLING CHARACTERISTICS OF GASOLENE WITH AND WITHOUT TIP Sindicates stalling occurred. N indicates no stalling occurred.

The results show clearly that when TIP was not used the engine stalledwithin /2 to 1 minute after the throttle was returned to the idleposition. Stalling is attributable to ice formation around the peripheryof the throttle plate when it was nearly closed at idle. During theseruns the ice was observed to build up, particularly in the throttleplate swivel area, thereby restricting the air flow. Such icing isespecially prevalent in the wintertime because the more volatile wintergrade gasolenes aggravate icing tendencies due to their greater tendencyto evaporate with resulting cooling. Also, weather conditions frequentlyintroduce enough moisture to create icing problems when relativehumidity of the atmosphere is above about 85% and the temperaturebetween about 35 and about 47 F. In contrast to the poor stallingcharacteristics displayed by the base gasolene under the test conditionsdescribed above, the gasolene containing TIP prevented ice build up inthe throttle plate zone as observed visually during the test and also asdemonstrated by the absence of stalling during 3 /2 minutes of engineoperation with the throttle in idle position during the above describedtest. It is, therefore, apparent that the addition of TIP to the basegasolene served to eliminate the stalling tendencies of the basegasolene. TIP is thus shown to be a superior gasolene additive in thatit not only reduced preignition problems as described above, but alsoreduces or eliminates carburetor icing and prevents rusting asdetermined by ASTM Method D665-54 Test for Rust-PreventingCharacteristics of Oil, when performed at ambient temperature.

While the invention has been described above with respect to certainpreferred embodiments thereof, it will be understood by those skilled inthe art that various changes and modifications may be made withoutdeparting from the spirit and scope of the invention and it is intendedto cover all such changes and modifications in the appended claims.

I claim:

1. A liquid compound having the formula:

wherein M is a metal selected from the group consisting of titanium andzirconium and each of R and R is a branched chain alkyl having up toabout 30 carbon atoms.

2. A liquid compound having the formula:

wherein M is a metal selected from the group consisting of titanium andzirconium, X is a number equal to the valence of the metal M and each ofR and R is a branched chain alkyl having up to about 30 carbon atoms.

3. A compound of claim 2 in which R and R are identical branched chainalkyls.

4. Titanium tetra (bis(2-ethylhexyl) orthophosphate).

5. Zirconium tetra (bis(2 ethylhexyl) orthophosphate).

6. Titanium tri (bis(2-ethylhexyl) orthophosphate).

7. Zirconium tri (bis(2-ethylheXyl)i orthophosphate).

8. A compound of claim 1 wherein the metal is titanium.

References Cited by the Examiner UNITED STATES PATENTS 2,228,659 1/1941Farrington et al. 252-35 2,346,155 4/1944 Denison et al 25232 2,480,6738/1949 Reitf et al 260-429.5 XR 2,881,062 4/1959 Bishop 4469 2,885,4175/1959 Heyden 260429.5 XR 2,913,469 11/1959 Russell 260429.5 2,926,1832/1960 Russell 260--429.5 2,948,599 8/1960 Orloft et al. 4469 3,055,9259/1962 Hartle 260--437 TOBIAS E. LEVOW, Primary Examiner.

JULIUS GREENWALD, ABRAHAM H. WINKEL- STEIN, Examiners.

M. WEINBLATT, W. J. VAN BALEN, H. M. S. SNEED,

Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,275,668 September 27, 1966 Anthony J. Revukas It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected below.

Column 4, line 74, for "(0ctylphenylorthophosphate-" read(octylphenyl)orthophosphate column 5, lines 67 to 70, the

formula should appear as shown below instead of as in the patent:

column 6, line 15, the formula should appear as shown below instead ofas in the patent:

Signed and sealed this 29th day of August 1967.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner ofPatents

2. A LIQUID COMPOUND HAVING THE FORMULA:
 5. ZIRCONIUM TETRA(BIS(2 -ETHYLHEXYL) ORTHOPHOSPHATE).
 7. ZIRCONIUM TRI(BIS(2-ETHYLHEXYL)ORTHOPHOSPHATE).